Toyota RAV4 (XA40) 2013-2018 Service Manual: Symptom confirmation and diagnostic trouble code
Hint:
The diagnostic system in the rav4 has various
functions.
- The first function is the diagnostic trouble code
(dtc) check. A dtc is a code stored in the ecu
memory whenever a malfunction in the signal circuits
to the ecu occurs. In a dtc check, a previous
malfunction's dtc can be checked by a technician
during troubleshooting.
- Another function is the input signal check, which
checks if the signals from various switches are sent to
the ecu correctly.
By using these functions, the problem areas can be
narrowed down and troubleshooting is more effective.
Diagnostic functions are incorporated in the following
system in the rav4.



- In the dtc check, it is very important to determine
whether the problem indicated by the dtc is either: 1)
still occurring, or 2) occurred in the past but has since
returned to normal. In addition, the dtc should be
compared to the problem symptom to see if they are
related. For this reason, dtcs should be checked
before and after confirmation of symptoms (i.E.,
Whether or not problem symptoms exist) to determine
current system conditions, as shown in the flowchart
below.
- Never skip the dtc check. Failing to check dtcs
may, depending on the case, result in unnecessary
troubleshooting for systems operating normally or
lead to repairs not related to the problem. Follow the
procedures listed in the flowchart in the correct order.
- The following flowchart shows how to proceed with
troubleshooting using the dtc check. Directions from
the flowchart will indicate how to proceed either to
dtc troubleshooting or to the troubleshooting of each
problem symptom.


The problem is still occurring in a place other than the
diagnostic circuit (the dtc displayed first is either for a past
problem or a secondary problem).
Hint:
In troubleshooting, confirm that the problem symptoms
have been accurately identified. Preconceptions should be
discarded in order to make an accurate judgment. To
clearly understand w ...
Hint:
The most difficult case in troubleshooting is when no
problem symptoms occur. In such a case, a thorough
problem analysis must be carried out. A simulation of the
same or similar conditions ...
Other materials:
Occupant classification ecu malfunction
Description
Dtc b1795 is recorded when a malfunction is detected in the occupant
classification ecu.
Troubleshoot dtc b1771 first when dtc b1771 and b1795 are output simultaneously.
Wiring diagram
Inspection procedure
Check for dtc
Turn the ignition switch on, and wait ...
Control module communication bus off
Description
The power steering ecu receives signals from the ecm and the skid control ecu
via the can
communication system.
Hint:
When 2 or more dtcs starting with [u] are output simultaneously, inspect
the connectors and wire
harness of each ecu.
If dtc u0105/41 is output, fi ...
On-vehicle inspection
Hint:
When pressing the switch for 0.3 Seconds or less, the roof
glass moves but auto operation does not operate.
Check auto operation
Turn the ignition switch on.
When the roof glass is fully closed, press the slide
open switch for 0.3 Seconds or more. Check that
the roof glass au ...